Fire box size

[NH/Pete]

I'll be using a flat pan measuring 18"x6' this year on a block arch.

What size should the fire box be?

[Paperman]

Id say long enough to be able to get your wood in but no so long you cant keep a good fire in the back.

[jasonl6]

I have always heard you need to have your firebox come back a couple feet past the front of your rear pan. Since your using a flat pan i would make your firebox 30" long and slop it up to be withing a couple inches of the bottom of your pan.

When i built my arch i made my firebox about 5' deep on my 8' rig. It's a raised flue setup. With the AUF & AOF and 4' plus wood she really roars.

Jason

[RileySugarbush]

No more than 2 feet deep by full width. If you have a reasonably sized stack then I suggest you skip the slope and bring the back of the firewall right up to within 2 inches of so of the bottom of the flat pan. If you feel the need for a slope, start it well up from the grate and don't slope it more than 2 feet back.

Think about getting enough exposed grate to combust the amount of fuel you need, and maximizing the area of the pan exposed to the flue gases. Also, think about adding a simple under air blower. Even a little air will really help and will prevent the buildup of coals that is easy to get in a block arch.

[NH/Pete]

No more than 2 feet deep by full width. If you have a reasonably sized stack then I suggest you skip the slope and bring the back of the firewall right up to within 2 inches of so of the bottom of the flat pan. If you feel the need for a slope, start it well up from the grate and don't slope it more than 2 feet back.

Think about getting enough exposed grate to combust the amount of fuel you need, and maximizing the area of the pan exposed to the flue gases. Also, think about adding a simple under air blower. Even a little air will really help and will prevent the buildup of coals that is easy to get in a block arch.

Thank you all for the replies. What would you recommend for a stack size?

[C.Wilcox]

I have a 2X4 flat pan and my firebox is about 20" deep with a vertical back wall as Riley described. I also have a forced air draft blowing air from below the fire. The front part of my pan rolls like crazy, but the back half is really lazy unless I split all my wood in to twig size pieces and throw handful after handful in the fire. If I had to do it over I would have made the firebox at least 24 inches deep and sloped the back wall to about the 3' mark on the pan.